Effect and Mechanism of Epigallocatechin-3-gallate on Learning and Memory Abilities of Epileptic Rats / 中国实验方剂学杂志

ObjectiveTo investigate the effects of epigallocatechin-3-gallate （EGCG） on learning and memory abilities of amygdala electrical kindling-induced epilepsy in rats and its mechanism. MethodMale SD rats were randomly divided into the normal group， model group， intervention group （model+25 mg·kg-1 EGCG）， and EGCG group （25 mg·kg-1 EGCG）. Rats in the EGCG group were only given EGCG intraperitoneal injection， those in the normal group were only given electrode implantation， and those in the other experimental groups were given amygdala electrical kindling stimulation to establish a chronic kindling epilepsy model. EGCG was injected intraperitoneally daily before electrical stimulation. Twenty-four hours after the last electrical stimulation， the escape latency and percentage of target quadrant were recorded by the Morris water maze. Twenty-four hours after the behavioral test， rats in each group were sacrificed by decapitation. The number of hippocampal neurons was observed by Nissl staining. The thickness of postsynaptic density in the hippocampus， synaptic cleft， length of active zone and the curvature of synaptic interface were observed by transmission electron microscopy （TEM）. The expressions of synapse-related proteins synaptotagmin （Syt）， postsynaptic density-95 （PSD-95） and Kalirin-7 in the hippocampus were examined by Western blot. ResultCompared with those in the normal group， the escape latency was significantly prolonged （P<0.05， P<0.01） and the target quadrant ratio was significantly decreased in the model group （P<0.05）. The number of hippocampus neurons decreased significantly （P<0.01）. The synaptic cleft of the hippocampus was widened significantly， and the length of active zone and the thickness of postsynaptic density were significantly decreased （P<0.05， P<0.01）. The expressions of synapse-related proteins Syt， PSD-95 and Kalirin-7 in the hippocampus were significantly decreased （P<0.05，P<0.01）. Compared with those in the model group， the escape latency was significantly shortened and the percentage of target quadrant was significantly increased in the intervention group （P<0.05， P<0，01）. The number of hippocampal neurons significantly increased （P<0.01）. The synaptic cleft of the hippocampus was significantly shortened， and the length of active zone and postsynaptic density were significantly increased （P<0.05， P<0.01）. The expressions of synaptic related proteins Syt， PSD-95 and Kalirin-7 were significantly increased （P<0.05， P<0.01）. ConclusionEGCG can effectively improve cognitive dysfunction after epilepsy. Its protective effect may be achieved by protecting the ultrastructure of hippocampal synapses and regulating the expressions of synapse-related proteins Syt， PSD-95 and Kalirin-7.

Inhibitory effects of epigallocatechin-3-gallate on the pathogenic properties of P. gingivalis in vitro / 口腔疾病防治

Objective @#To explore the antibacterial activity of epigallocatechin-3-gallate (EGCG) on P. gingivalis and the inhibitory effects on matrix metalloproteinases (MMPs) production induced by P. gingivalis.@*Methods@# The antimicrobial effect of EGCG against planktonic cultures and biofilms of P. gingivalis was evaluated using microplate dilution assays. The microstructural changes in biofilms were studied using scanning electron microscopy (SEM). The inhibitory effect of EGCG on arginine gingipain (Rgp) and lysine gingipain (Kgp) activity of P. gingivalis was evaluated using synthetic chromogenic peptides and fluorogenic substrates. Enzyme-linked immunosorbent assay (ELISA) and qRT-PCR analysis were used to assess MMP-1 and MMP-2 mRNA expression and secretion by human gingival fibroblasts (HGFs) stimulated with P. gingivalis in the presence or absence of EGCG, respectively. @*Results @# The MIC and MBC of EGCG against P. gingivalis were 62.5 μg/mL and 500 μg/mL, respectively. EGCG can not only inhibit the biofilm formation of P. gingivalis but also has a scavenging effect on mature biofilms and can affect their viability. Additionally, 10 μg/mL and 50 μg/mL of EGCG inhibited the proteinase activities of Rgp and Kgp, respectively (P < 0.05). Finally, the mRNA expression and secretion of MMP-1 and MMP-2 by HGFs stimulated by P. gingivalis were significantly inhibited by 50 μg/mL of EGCG (P < 0.05). @*Conclusion@#EGCG exhibits antimicrobial effects against P. gingivalis and reduces the expression of MMPs by HGFs.

Integrating network pharmacology and pharmacological evaluation for deciphering the mechanism of (-)-epigallocatechin-3-gallate alleviating ethanol-inducedendothelial cells injury / 中国药理学与毒理学杂志

Objective To investigate the potential therapeutic targets and pharmacological mechanism of (-)-epigal?locatechin-3-gallate (EGCG) based on network pharmacology and experimental verification. METHODS The druggability of EGCG was measured by the traditional Chinese medicine systems pharmacology (TCMSP) server, and potential tar?gets of EGCG were identified by Pharm Mapper and Drug Repositioning and Adverse drug Reaction via Chemical-Pro?tein Interactome (DRAR-CPI). The potential targets were imported into GeneMANIA database to obtain the protein-pro?tein direct interaction network, and target physical interaction, co-expression, prediction, genetic interaction, and shared protein domains. The biological process, molecular functions, cellular components and KEGG signaling pathways of potential targets were analyzed using DAVID database. For further study, ethanol was used to establish a model of endothelial injury in vitro. The cell viability was assayed by MTT method, the cellular apoptosis was stained by Annexin V/PI, and the expression levels of Bcl-2, Bax and cleved-caspase-3 were tested by Western blotting. Then, JC-1 and nuclear translocation of NF-κB experiments were used to study the mitochondrial membrane potential and nuclear trans?location. RESULTS The oral availability of EGCG was 55.09％ (≥ 30％) and drug-like index was 0.77 (≥ 0.18), which were considered pharmacokinetically active. 17 potential targetable proteins of EGCG were predicted by Pharm Mapper and DRAR-CPI. Further research showed that 68.13％ displayed similar co-expression characteristics, 26.11％ physical interactions, and 2.74％ shared the same protein domain. The depth network analysis results showed that the biofunc?tions of EGCG were mainly by regulating glutathione derivative biosynthetic process, glutathione metabolic process, nitrogen compound metabolic process etc.. via drug binding, catalytic activity, glutathione transferase activity, anion bind?ing etc.. in sarcoplasmic reticulum, spindle pole, microtubule cytoskeleton and cytoplasm. KEGG enrichment analysis showed that Glutathione metabolism, IL-17 signaling pathway, EGFR tyrosine kinase inhibitor resistance, PI3K-Akt sig?naling pathway and other pathways were involves in the biofunction of EGCG. The above analyses indicated that EGCG exerts its biofunction through antioxidant and anti-inflammatory mechanisms. The experimental results showed that etha?nol 20.0 mmol·L-1 decreased cell viability, Bcl-2 expression, and increased cell apoptosis, the intracellular ROS, as well as the expression of Bax and cleaved-caspase-3 of human endothelial cells. However, treatment of the cells with EGCG can significantly alleviate ethanol induced endothelial cells injury. Further study showed that EGCG significantly allevi?ates ethanol induced mitochondrial depolarization and nuclear translocation of NF-κB. CONCLUSIONS EGCG exerts pharmacological efficacies on ethanol induced endothelial cell injury through multi-target, multi-function and multi-path?way mode. Protective effect of EGCG on ethanol induced cell injury was mainly through alteration of mitochondrial func?tion and NF-κB translocation. Therefore, EGCG have great potential in protecting against endothelial dysfunction of the persons who are chronically abuse of ethanol. This study also provides a new understanding of EGCG in clinical applica?tion on cardiovascular and cerebrovascular diseases.

Potential effect of EGCG on the anti-tumor efficacy of metformin in melanoma cells / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

Metformin, a first-line drug for type 2 diabetes mellitus, has been recognized as a potential anti-tumor agent in recent years. Epigallocatechin-3-gallate (EGCG), as the dominant catechin in green tea, is another promising adjuvant agent for tumor prevention. In the present work, the potential effect of EGCG on the anti-tumor efficacy of metformin in a mouse melanoma cell line (B16F10) was investigated. Results indicated that EGCG and metformin exhibited a synergistic effect on cell viability, migration, and proliferation, as well as signal transducer and activator of transcription 3/nuclear factor-κB (STAT3/NF-κB) pathway signaling and the production of inflammation cytokines. Meanwhile, the combination showed an antagonistic effect on cell apoptosis and oxidative stress levels. The combination of EGCG and metformin also differentially affected the nucleus (synergism) and cytoplasm (antagonism) of B16F10 cells. Our findings provide new insight into the potential effects of EGCG on the anti-tumor efficacy of metformin in melanoma cells.

Effects of epigallocatechin-3-gallate on cognitive function and hippocampal autophagy in APP/PSI transgenic mice / 中国药理学通报

Aim To explore mechanism of epigallocatechin-3-gallate (EGCG) on alleviation of hippocampal neuronal autophagy in APP/PSI transgenic mice. Methods 8-month old APP/PSI transgenic mice were randomly divided into three groups;model group (Tg), EGCG low dose group (Tg/EGCG-L), high dose group (Tg/EGCG-H). C57BL/6J mice were utilized as control. Learning and memory were detected by Morris water maze test. The hippocampal ULK1, P62, LC3 I I / LC3 I,mT0R and Aß M2 expressions were detected by Western blot, immunohistochemical staining and ELISA. Results Compared with NT mice, Tg mice showed a marked prolongation of the escape latency in MWM test (P <0. 05). Decreased ULK1 expression and increased P62, LC3 II/LC3 I and A ßM 2 were detected (P < 0. 05). EGCG-treated group showed marked improvement of all these abnormal changes (P < 0. 05). Conclusions EGCG treatment is able to improve cognitive function, which may be attributed to ameliorated autophagic networks dysfunction and reduced Aß plaques in the the hippocampi of APP/PS1 transgenic mice.

Analysis Of Fatty Acids From Oil Of Green Tea (CAMELLIA Sinensis L) By Gas Chromatography Coupled With Flame Ionization Detector And Its Anticancer And Antibacterial Activity In Vitro

Objective: Tea is a widely consumed beverage worldwide. The effect of green tea is mainly due to its high polyphenols-(-) epigallocatechin-3-gallate (EGCG) content in the culture of cancer cell and bacterial cells. The present work was carried out to investigate the efficacy of green tea oil (GTO) against cancer cells and bacterial cells. Methods: In this study green tea oil was prepared from green tea for different experiment and determination of fatty acids profile from green tea oil. In the present study, peripheral blood lymphocyte (PBL) was chosen as human peripheral blood lymphocytes and blood cancer MCF-7 cells were chosen as human cancer cells. To fulfill our aims and also to evaluate the activity of this phytomedicine against normal lymphocytes and cancer cells the cell samples were divided into 26 experimental groups in the following ways. Each Petri dish contains 2 X 105 cells. Results: GTO shows a potent anticancer agent but nontoxic to normal cells. The GTO decreases the reduced glutathione (GSH) level and increase the oxidized glutathione (GSSG) level significantly (P<0.05) in MCF-7 cells. But in lymphocytes the GSH level and GSSG level were almost the same with the control group but doxorubicin (DOX) significantly decreased the GSH and increase the GSSG level. Green tea oil treatment causes generation of reactive oxygen species (ROS) in MCF-7 cells revealed by DCFH2DA staining. Agar diffusion test shows the GTO is effective against multi-drug resistant bacteria. Conclusion: This phytomedicine has a potent anticancer activity without damaging the normal lymphocytes. So, this drug can be used for further treatment of anticancer and antibacterial.

Epigallocatechin-3-gallate ameliorates lipopolysaccharide-induced acute lung injury by suppression of TLR4/NF-κB signaling activation

Acute lung injury (ALI) is a serious clinical syndrome with a high rate of mortality. The activation of inflammation is well-recognized as a vital factor in the pathogenesis of lipopolysaccharide (LPS)-induced ALI. Therefore, suppression of the inflammatory response could be an ideal strategy to prevent ALI. Epigallocatechin-3-gallate (EGCG), mainly from green tea, has been shown to have an anti-inflammatory effect. The aim of the study was to explore whether EGCG alleviates inflammation in sepsis-related ALI. Male BALB/C mice were treated with EGCG (10 mg/kg) intraperitoneally (ip) 1 h before LPS injection (10 mg/kg, ip). The results showed that EGCG attenuated LPS-induced ALI as it decreased the changes in blood gases and reduced the histological lesions, wet-to-dry weight ratios, and myeloperoxidase (MPO) activity. In addition, EGCG significantly decreased the expression of pro-inflammatory cytokines tumor necrosis factor (TNF)-α, interleukin (IL)-1β, and IL-6 in the lung, serum, and bronchoalveolar lavage fluid, and alleviated the expression of TLR-4, MyD88, TRIF, and p-p65 in the lung tissue. In addition, it increased the expression of IκB-α and had no influence on the expression of p65. Collectively, these results demonstrated the protective effects of EGCG against LPS-induced ALI in mice through its anti-inflammatory effect that may be attributed to the suppression of the activation of TLR 4-dependent NF-κB signaling pathways.

Effect of epigallocatechin-3-gallate on radiation-induced esophagitis of rabbit / 中华放射医学与防护杂志

Objective To analyze the effect of epigallocatechin-3-gallate (EGCG) in radiation induced esophagitis of model rabbit.Methods Thirty male New Zealand rabbits were randomly divided into EGCG group,saline group,blank group.The rabbits in EGCG and saline groups were irradiated with 6 MV X-rays.The blank group did not receive radiation.After irradiation,rabbits were given with 440 μmol/L EGCG or saline three times a day in continuous 5 days.The scores of pathological changes of esophagus were observed by optical microscope.The serum levels of interleukine-1 beta (IL-1β),interleukine-6 (IL-6),transforming growth factor-β (TGF-β) and tumor necrosis factor-α (TNF-α) were detected by enzyme linked immunosorbent assay.The expression levels of 67KD laminin receptor (67LR)was detected by immunohistochemistry.Results After treatment,the scores of pathological changes of esophagus in blank group,saline group,EGCG group were 0,3.9± 1.10 and 2.80±0.92,respectively.At different time points after drug treatment,the levels of serum inflammatory factors among three groups were significantly different (F=23.66-236.32,P＜0.05).The expressions of 67LR in esophageal tissue of 3 groups were also significantly different (F=585.38,P＜0.05).Conclusions EGCG reduced radiationinduced esophagitis in rabbits by decreasing the levels of serum inflammatory factors,which may be related to the expression of 67LR protein.

Effect of epigallocatechin-3-gallate on airway inflammation and Treg/Th17 immune balance of mice with obese asthma / 吉林大学学报(医学版)

Objective: To investigate the regulatory effect of epigallocatechin-3-gallate (EGCG) on the immune imbalance of regulatory T lymphocytes/helper T lymphocytes 17 (Treg/Th17) in the mice with obese asthma, and to provide the basis for the treatment of obese asthma by EGCG. Methods: A total of 40 C57BL/6J mice were randomly divided into normal control group (fed with chow diet), obese group (fed with high fat diet), obese asthma group [fed with high fat diet and sensitized and challenged with ovalbumin (ova)], EGCG intervention group (20 mg middot; kg-1 EGCG was administered intraperitoneally 1 h before challenge of OVA) and dexamethasone intervention group (2 mg middot; kg-1 dexamethasone was administered intraperitoneally 1 h before challenge of OVA), and there were 8 mice in each group. The edhanced pause (Penh) values of the mice in various groups were measured with non-invasive lung function instrument; the pathomorphology of lung tissue of the mice in various groups were observed by HE staining, and the inflammation scores were evaluated by semi-quantitative method for HE staining section; the levels of interleukin-10 (IL-10) and interleukin-17A (IL-17A) in bronchoalveolar lavage fluid (BALF) and adiponectin and leptin in serum of the mice in various groups were detected by ELISA method, and the percentages of Treg and Th17 in spleen tissue of the mice in various groups were detected by flow cytometery. Results: Compared with normal control group, the body weight of the mice in obese group was increased (P<0. 05); it was 1. 67 times the average weight of the mice in normal control group. Compared with normal control group, the Penh value and inflammation score of the mice in obese asthma group were increased (P< 0. 05); the leptin level in serum of the mice in obese asthma group was increased (P<0. 05); the IL-17 level in BALF of the mice in obese asthma group was increased (P<0. 05) and IL-10 level in BALF of the mice in obese asthma group was decreased (P<0. 05); the percentage of Th17 in spleen tissue of the mice in obese asthma group was increased (P<0.05) and the percentage of Treg in spleen tissue of the mice in obese asthma group was decreased (P<0. 05). Compared with obese asthma group, the Penh value and inflammation score of the mice in EGCG intervention group were decreased (P<0. 05); the leptin level in serum of the mice in EGCG intervention group was decreased (P<0. 05); the IL-17 level in BALF of the mice in EGCG intervention group was decreased (P<0. 05) and IL-10 level in BALF of the mice in EGCG intervention group was increased (P<0. 05); the percentage of Th17 in spleen tissue of the mice in EGCG intervention group was decreased (P<0. 05) and the percentage of Treg in spleen tissue of the mice in EGCG intervention group was increased (P < 0. 05). Conclusion: Treg/Th17 immune imbalance exists in the mice with obese asthma. EGCG could inhibit the airway inflammation and hyperresponsiveness in the mice with obese asthma and improve the Treg/Th17 immune imbalance.

Effect of epigallocatechin-3-gallate on radiation-induced esophagitis of rabbit / 中华放射医学与防护杂志

Objective@#To analyze the effect of epigallocatechin-3-gallate (EGCG) in radiation induced esophagitis of model rabbit.@*Methods@#Thirty male New Zealand rabbits were randomly divided into EGCG group, saline group, blank group. The rabbits in EGCG and saline groups were irradiated with 6 MV X-rays. The blank group did not receive radiation. After irradiation, rabbits were given with 440 μmol/L EGCG or saline three times a day in continuous 5 days. The scores of pathological changes of esophagus were observed by optical microscope.The serum levels of interleukine-1 beta (IL-1β), interleukine-6 (IL-6), transforming growth factor-β (TGF-β) and tumor necrosis factor-α (TNF-α) were detected by enzyme linked immunosorbent assay. The expression levels of 67KD laminin receptor (67LR) was detected by immunohistochemistry.@*Results@#After treatment, the scores of pathological changes of esophagus in blank group, saline group, EGCG group were 0, 3.9±1.10 and 2.80±0.92, respectively. At different time points after drug treatment, the levels of serum inflammatory factors among three groups were significantly different (F=23.66-236.32, P<0.05). The expressions of 67LR in esophageal tissue of 3 groups were also significantly different (F=585.38, P<0.05).@*Conclusions@#EGCG reduced radiation-induced esophagitis in rabbits by decreasing the levels of serum inflammatory factors, which may be related to the expression of 67LR protein.

Eight-week healing of grafted calvarial bone defects with hyperbaric oxygen therapy in rats

PURPOSE: The purpose of this study was to evaluate the synergistic effect of adjunctive hyperbaric oxygen (HBO) therapy on new bone formation and angiogenesis after 8 weeks of healing. METHODS: Sprague-Dawley rats (n=28) were split into 2 groups according to the application of adjunctive HBO therapy: a group that received HBO therapy (HBO group [n=14]) and another group that did not receive HBO therapy (NHBO group [n=14]). Each group was divided into 2 subgroups according to the type of bone graft material: a biphasic calcium phosphate (BCP) subgroup and an Escherichia coli-derived recombinant human bone morphogenetic protein-2-/epigallocatechin-3-gallate-coated BCP (mBCP) subgroup. Two identical circular defects with a 6-mm diameter were made in the right and left parietal bones of each rat. One defect was grafted with bone graft material (BCP or mBCP). The other defect was not grafted. The HBO group received 2 weeks of adjunctive HBO therapy (1 hour, 5 times a week). The rats were euthanized 8 weeks after surgery. The specimens were prepared for histologic analysis. RESULTS: New bone (%) was higher in the NHBO-mBCP group than in the NHBO-BCP and control groups (P<0.05). Blood vessel count (%) and vascular endothelial growth factor staining (%) were higher in the HBO-mBCP group than in the NHBO-mBCP group (P<0.05). CONCLUSIONS: HBO therapy did not have a positive influence on bone formation irrespective of the type of bone graft material applied after 8 weeks of healing. HBO therapy had a positive effect on angiogenic activity.

Improvement of the osteogenic potential of ErhBMP-2-/EGCG-coated biphasic calcium phosphate bone substitute: in vitro and in vivo activity

PURPOSE: The aim of this study was to evaluate the enhancement of osteogenic potential of biphasic calcium phosphate (BCP) bone substitute coated with Escherichia coli-derived recombinant human bone morphogenetic protein-2 (ErhBMP-2) and epigallocatechin-3-gallate (EGCG). METHODS: The cell viability, differentiation, and mineralization of osteoblasts was tested with ErhBMP-2-/EGCG solution. Coated BCP surfaces were also investigated. Standardized, 6-mm diameter defects were created bilaterally on the maxillary sinus of 10 male New Zealand white rabbits. After removal of the bony windows and elevation of sinus membranes, ErhBMP-2-/EGCG-coated BCP was applied on one defect in the test group. BCP was applied on the other defect to form the control group. The animals were sacrificed at 4 or 8 weeks after surgery. Histologic and histometric analyses of the augmented graft and surrounding tissue were performed. RESULTS: The 4-week and 8-week test groups showed more new bone (%) than the corresponding control groups (P<0.05). The 8-week test group showed more new bone (%) than the 4-week test group (P<0.05). CONCLUSIONS: ErhBMP-2-/EGCG-coated BCP was effective as a bone graft material, showing enhanced osteogenic potential and minimal side effects in a rabbit sinus augmentation model.

Research progress on molecular mechanism of epigallocatechin-3-gallate against cancer and its application / 中草药

Epigallocatechin-3-gallate (EGCG), as one of the main components of green tea, has a variety of biological activities. Both in vitro and in vivo experiments widely demonstrate that EGCG has anticancer activities. The molecular mechanism of EGCG against cancer was much complicated, and EGCG suppressed tumor cell proliferation and/or induced cell apoptosis through multi-pathways. This paper reviewed the anticancer molecular mechanism of EGCG, including EGCG anti-oxidantion, prooxidation, retardant of tumor cell cycle, inhibition of tumor cell angiogenesis, inducement of cancer cell apoptosis, and regulation of microRNA, summarized the research progress of three strategies for improving bioavailability of EGCG: nano-packaging technology, synergistic application and molecular modification, and looked into research and development on anticancer activity of EGCG.

Effect of epigallocatechin-3-gallate on oxidative stress and inflammation in 3T3-L1 adipocytes / 上海交通大学学报（医学版）

Objective • To explore the effect of epigallocatechin-3-gallate (EGCG) on oxidative stress and inflammation in 3T3-L1 adipocytes, and provide a theoretical basis for EGCG to prevent obesity and related chronic diseases. Methods • 3T3-L1 preadipocytes were differentiated to mature adipocytes by in vitro cell culture. The cells were divided into blank control group, and 1, 10 and 50 μg/mL EGCG groups. After 24 hour treatment, intracellular oxidative stress indicators glutathione (GSH), superoxide dismutase (SOD), and malondialdehyde (MDA) levels in the cells were measured. The levels of inflammatory indexes interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), and monocyte chemoattractant protein-1 (MCP-1) were tested by ELISA and realtime PCR, while the expression of nuclear factor E2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1) was tested by realtime PCR. Results • Compared with the control group, GSH and SOD levels in 3T3-L1 adipocytes increased in a dose-dependent manner after treatment of EGCG (both P<0.05), while MDA level in 3T3-L1 adipocytes decreased dose-dependently after treatment of EGCG (P<0.05). IL-6, MCP-1 and TNF-α levels in 3T3-L1 adipocytes supernatant declined significantly in a dose-dependent manner after treatment of 1, 10 and 50 μg/mL EGCG (all P<0.05). The expression levels of IL-6, MCP-1 and TNF-α in 3T3-L1 adipocytes were decreased in a dose-dependent manner after 24 h treatment of different concentrations of EGCG. Nrf2 and HO-1 mRNA levels in 3T3-L1 adipocytes increased significantly in a dose-dependent manner after treatment of 10 and 50 μg/mL EGCG (both P<0.05). Conclusion • EGCG plays an antioxidation and anti-inflammatory effects in 3T3-L1 adipocytes, which may be related to up-regulation of Nrf2/HO-1.

Research progresses of green tea extract epigallocatechin-3-gallate on preventing and treating radiation injury / 中华放射医学与防护杂志

Radiotherapy is one of the important cancer therapy methods that can lead to tissue damage including radiation lung injury,radiation esophageal injury,radiation skin damage and abnormal changes in hemopoietic system and immune system.Epigallocatechin-3-gallate (EGCG) is the most abundant catechin in green tea.It has been demonstrated that EGCG has biological effects of antiinflammatory,antioxidant,anti-apoptosis and regulating immunity.Recently some studies of cell and animal models suggest that EGCG has radioprotective effect,but few clinical research was reported.In this review,the studies about EGCG in preventing and treating radiation injury were summarized from antiradiation mechanism in order to enhance the understanding of the potential clinical application of EGCG.

Evaluation method for compatibility of compounds in fluorescence resonance energy transfer model to screen β-secretase inhibitors / 中国药理学与毒理学杂志

OBJECTIVE To develop a method to evaluate the compatibility of compounds in the fluorescence resonance energy transfer (FRET) model for β-secretase (BACE1) inhibitor screening.METHODS Two commercially available BACE1 inhibitor screening systems based on FRET were selected to evaluate the BACE1 inhibitory activities of (-)-epigallocatechin-3-gallate (EGCG) and Compound 1 according to the supplier's protocol.The inhibitory rates and slopes of the catalytic curves of the inhibitors were calculated.The effect of inhibitors on the fluorescence intensity of the systems were quantitatively calculated and the comparatively evaluated.RESULTS EGCG,a reported non-competitive inhibitor of BACE1,directly induced the reduction of fluorescence intensity of one of the systems.The slope of the line with the addition of EGCG (10.8±2.6) conformed to that of the line of EGCG inhibition (10.2±3.4),which indicated that EGCG was a pseudo-positive inhibitor of BACE1.Compound 1 had little effect on the fluorescence intensity of the systems,so the inhibitory activity of Compound 1 was confirmed.The compounds which showed inhibitory activity in preliminary screening should be checked in the blank control without BACE1 to calibrate the effect of compound on the system fluorescence intensity.The applicability of the tested compounds in the screening system could thus be evaluated to prevent pseudo-positive results.CONCLUSION This fluorescence calibration method with compound control can be universally used for assays based on FRET theory to evaluate the applicability of tested BACE1 inhibitors.

Effects and mechanism of epigallocatechin gallate on white adipose tissue angiogenesis in high fat diet rats / 中华临床营养杂志

Objective To investigate the effects and mechanism of (-)-epigallocatechin-3-gallate (EGCG) on white adipose tissue angiogenesis in high fat diet rats.Methods Twenty-four male weaning SD rats were randomly divided into normal control group,high fat diet group and EGCG intervention group,8 rats in each group.Normal control group were fed with normal diet,high-fat diet group were fed with high-fat diet,EGCG intervention group were fed with high-fat diet along with intragastric administration of 200 mg/ (kg · d) EGCG.After 8 weeks,the rats were sacrificed.The adipocyte size and vascular density of the abdominal adipose tissue in rats in each group were observed under the microscope.The serum vascular endothelial growth factor (VEGF) concentration was detected by Elisa Kit.RT-PCR was used to detect the expression of VEGF,nuclear factor E2 (Nrf2),heme oxygenase-1 (HO-1),catalase (CAT),SOD,GPx,interleukin-6 (IL-6) and monocyte chemoattractant protein-1 (MCP-1) mRNA.Results The adipocyte size,number of vascular/each adipocyte,serum VEGF concentration and VEGF mRNA expression in adipose tissue of high fat diet group were significantly higher than those of normal control group (all P＜0.05).EGCG can significantly reduce the above indicators of high fat diet group (all P＜0.05).The expression of Nrf2,HO-1,SOD,GPx and CAT mRNA in adipose tissue of EGCG group was significantly higher than those in high fat diet group and normal control group (all P＜0.05).The expression of MCP-1 and IL-6 mRNA in adipose tissue of EGCG group was significantly lower than that in high fat diet group (all P＜0.05).Conclusion EGCG can decrease the production of serum VEGF,vascular density and the expression of VEGF mRNA in white adipose tissue of high fat diet rats,and inhibit the angiogenesis in white adipose tissue possibly due to its up-regulation of Nrf2/HO-1 pathway to increase the expression of antioxidant enzymes (SOD,CAT,GPx),reduce ROS production and decrease the inflammatory response.

Potential benefit of (-)-epigallocatechin-3-gallate for macrovascular complications in diabetes

Vascular problems are the most common complications in diabetes. Substantial evidence from epidemiological and pathophysiological studies show that hyperglycemia is a major risk factor for macrovascular complications in patients with diabetes. (-)-Epigallocatechin-3-gallate (EGCG), the major catechin derived from green tea, is known to exert a variety of cardiovascular beneficial effects. The protective effects of EGCG in diabetes are also evident. However, whether EGCG is beneficial against macrovascular complications that occur in diabetes remains unknown. Our previous studies demonstrated that treatment of EGCG inhibits high glucose-induced vascular smooth muscle cell proliferation and suppresses high glucose-mediated vascular inflammation in human umbilical vein endothelial cells. Therefore, we hypothesize that EGCG might be an effective potential candidate to reduce the macrovascular complications in diabetes.

Antibacterial efficacy of epigallocatechin -3 - gallate against streptococcus mutans: a systematic review / Eficacia antibacteriana de la epigalocatequina-3-galato contra el Streptococcus mutans: Revisión sistemática

Background: Green tea, obtained from the Camellia sinensis, is one of the most popular drinks worldwide and has recently been in the focus of scientific research due to its beneficial effects on general health. Several studies suggest that, among the polyphenols found on green tea, epigallocatechin-3-gallate (EGCG) is the most bioactive compound and is responsible for its antibacterial activity. Purpose: To conduct a qualitative systematic review of literature evaluating the antibacterial efficacy of EGCG against Streptococcus mutans (S. mutans). Methods: Relevant published studies included in the Pubmed (1966- June 2015), Scopus (1960- June 2015), Web of Science (1900- June 2015), and Google Scholar databases were identified. Publications of in vitro studies, which studied EGCG antibacterial efficacy against S. mutans, were extracted and pooled in a table. The evaluation included inhibition zone measures, reduction of the number of microorganisms, and biofilm formation. Results: Twelve studies were selected to compose this systematic review. Eleven of them showed that EGCG has antibacterial efficacy against S. mutans. Conclusions : In vitro evidence available confirms the antibacterial activity of EGCG against S. mutans.

Antecedentes: El té verde, obtenido de la Camellia sinensis, es una de las bebidas más populares en el mundo y ha estado recientemente en el foco de atención de la investigación científica por sus efectos benéficos en la salud general. Varios estudios sugieren que, entre los polifenoles encontrados en el té verde, la epigalocatequina-3-galato (EGCG) es el compuesto más bioactivo y es el responsable de su actividad antimicrobiana. Objetivo: Realizar una revisión sistemática cualitativa de la literatura donde se evalúe la actividad antibacteriana de la EGCG contra el Streptococcus mutans (S. mutans). Métodos: Se identificaron estudios relevantes incluidos en las bases de datos bibliográficas Pubmed (1966-junio del 2015), Scopus (1960-junio del 2015), Web of Science (1900- junio del 2015) y Google Académico. Los datos de estudios in vitro que investigaron la eficacia antibacterial de la EGCG contra el S. mutans se seleccionaron y organizaron en una tabla. La evaluación de los estudios incluyó los criterios: medidas de las zonas de inhibición, reducción del número de microorganismos y formación de biopelícula. Resultados: Se seleccionaron 12 estudios para la revisión sistemática. Once de ellos comprobaron la eficacia antibacteriana de la EGCG contra el S. mutans. Conclusiones: La evidencia in vitro disponible confirma que la EGCG tiene un efecto antibacteriano contra el S. mutans.

Effects of epigallocatechin-3-gallate modification on the bonding stability of an etch-and-rinse adhesive to intraradicular dentin / 中华口腔医学杂志

Objective@#To evaluate the effects of epigallocatechin-3-gallate (EGCG) modification on the bonding stability of an etch-and-rinse adhesive to intraradicular dentin, and to find a new strategy to improve the stability of bonding interface. @*Methods@#EGCG was incorporated into Single Bond 2 (SB2) with the concentration of 200 mg/L and 400 mg/L respectively to fabricated experimental adhesives group A and group B, while Single Bond 2 without EGCG was used as control group. Laser scanning confocal microscope (LSCM) and scanning electron microscope (SEM) were used to observe the bacterial biofilm adherent to the surface of the cured adhesive. Micro-Raman spectrum was used to test the degree of conversion (DC) of adhesives. The push-out bond strength of instant testing and aging with thermocycling for 5 000 times were also tested. @*Results@#Group A and group B showed inhibiting effect on the biofilm formation of Enterococcus faecalis and performed better with higher concentration. No significant differences were detected in DC among group A ([69.73±0.68]%), group B ([69.03±1.65]%) and control group ([70.06±1.62]%) (P>0.05), and the immediate push-out bond strength of control group ([10.45±2.00] MPa) was not compromised compared to group A ([10.02±2.03] MPa) and group B ([9.95±3.03] MPa) (P>0.05). After thermocycling for 5 000 times, group A ([7.01±1.39] MPa) and group B ([7.62±1.88] MPa) showed significantly higher push-out bond strength than control group did ([5.08±1.56] MPa) (P<0.05). @*Conclusions@#EGCG modified etch-and-rinse adhesives showed anti-bacterial effect and enhanced bonding stability of intraradicular dentin-adhesive interfaces.